Tiny Tip: Determining capacity in an emergency – The CURVES Mnemonic

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Determining capacity in a patient that needs to make an emergency medical decision can be a huge challenge for emergency physicians with substantial legal and patient-oriented consequences. As emergency medicine providers we need to be able to make this determination confidently and decisively. By preparing our approach in advance we can be more confident in our decisions.

In November 2014, EM:RAP (check it out!) had a great segment on decision making capacity and covered the article:

Chow, G. V., Czarny, M. J., Hughes, M. T., & Carrese, J. A. (2010). CURVES: a mnemonic for determining medical decision-making capacity and providing emergency treatment in the acute setting. CHEST Journal, 137(2), 421-427.

It provides a concise, applicable approach using the CURVES mnemonic

C – Choose and Communicate – Can the patient make and communicate a choice without coercion?
U – Understand – Does the patient understand the risks, benefits, alternatives, and consequences of their decision?
R – Reason – Is the patient able to reason and provide logical explanations for their decision?
V – Values – Is the decision consistent with the patient’s values?
E – Emergency – Is there a serious or imminent risk to the patient’s well-being?
S – Surrogate – Is there a surrogate decision maker available?

The first four letters (CURV) assess whether or not the patient has decision-making capacity. A patient can be considered to have capacity in a given situation if they can communicate their decision, demonstrate their understanding of their situation, and show that they have a reasonable thought process that is consistent with their values. The final two letters (ES) determine whether treatment can proceed with implied consent in a patient lacking capacity. Treating with implied consent is only appropriate when the patient does not have capacity to make the decision (CURV), it is an emergency, AND there is no surrogate decision maker available.

Notably, the articles stresses that capacity is not an all-or-none phenomenon and can change both over time and depending on the decision under consideration. For example, an inebriated trauma patient may have capacity to decide to accept or decline pain medication but not have the capacity to consent or reject a life-saving surgical intervention.

What do you think of the CURVES mnemonic? As outlined in the referenced article, there are many other ways to assess consent – how do you assess capacity in your emergency department?

Peer reviewed by Teresa Chan (@TChanMD)

Dr. Brent Thoma is a medical educator, blogging geek, and trauma/emergency physician who works at the University of Saskatchewan College of Medicine. He founded BoringEM and is the CEO of CanadiEM.
BoringEM has been 'bringing the boring' to emergency medicine since 2012. In 2016 this Canadian blog brought its content to CanadiEM.